gmsumsion wrote:I'm glad I found this thread. I purchased my trailer used last summer. The batteries (2 12v) have never held a charge. I am heading out this weekend and will be dry camping so I'm going to replace the batteries.

Looks like I ought to go with two 6v batteries instead of the two 12 volts, or do I need to get 4 6 volts to replace the 2 12 volts? Also, I'm guessing that I need to connect the 6v batteries differently than the 12 volts have been. Is that right?

To give you a better idea of how I use my trailer . . . it's mostly dry camping. We have a place in the mountains and when the weather gets good I'll take the trailer up there and leave it for most of the summer. We might haul it to a few places during the summer, but mostly it serves as a surrogate for a cabin. It would be great if I could count on the batteries holding a charge for a couple of weeks between visits from me. When I go up, I can run the generator to top off the charge when necessary. I also have a single 15 watt solar panel charger. Maybe I need more than that if the refrigerator will be running (on propane) in our absence.

You guys are great. I appreciate your knowledge. Thanks in advance for sharing.

The 6 volt batteries will have a higher amp-hour rating than the 12 volt batteries. So if you replace 2 12 volt batteries with 2 6 volt batteries, you will probably have about the same number of total amp hours. You do have to connect the 6 volt differently. If only 2 6 volt batteries are used, hook them together in series, and then hook that to the trailer wiring. If using 4 6 volt batteries, you have to use what is called a series-parallel configuration. Your best bet would be to do a Google search on that term so that you can get some drawings. There are also some members here (BFL13, PianoTuna come to mind right away) who can supply you with diagrams.

Your 15 watt solar panel would maintain your batteries between visits if there was no load on them. But things like the control board in the fridge, the propane alarm, the stereo system, etc. eat power 24/7 while your solar panel only supplies power during the day. Then there is the self discharge of flooded batteries which can be 5 to 10 percent per month (lower rate is at lower temperatures). If this is an issue for you, you could consider AGM batteries which have a self discharge rate of about 1% per month and can be recharged from you generator quicker, provided you have a high output 3 stage smart charger. The down side is that AGM batteries will cost you noticeably more than other batteries like flooded 6 volt golf cart batteries.

gmsumsion wrote:Thanks ERS. How many watts of solar panels will I need to keep things charged and healthy, given the use by the fridge, alarm, stereo system, etc?

I don't think I do have a high output 3 stage smart charger. I'm assuming that would be an upgrade, and I know I haven't done it.

If you can generate about 3 amps for 5 or 6 hours a day, that should suffice. So something around 48 to 60 watts would work. You may already have a three stage smart charger. Take a look at your converter. Get the brand and model number and look it up on the internet. If it has a bulk (or boost) mode, absorption mode, and float mode, it is a three stage unit.

gmsumsion wrote:Thanks ERS. How many watts of solar panels will I need to keep things charged and healthy, given the use by the fridge, alarm, stereo system, etc?

I don't think I do have a high output 3 stage smart charger. I'm assuming that would be an upgrade, and I know I haven't done it.

If you can generate about 3 amps for 5 or 6 hours a day, that should suffice. So something around 48 to 60 watts would work. You may already have a three stage smart charger. Take a look at your converter. Get the brand and model number and look it up on the internet. If it has a bulk (or boost) mode, absorption mode, and float mode, it is a three stage unit.

That's helpful information. Thanks. Now, um, for the newbie question of the day . . . wait for it . . where do I find the converter? Sorry.

Is it by the control panel where I turn on the pump, check levels, etc?

I don't think I do have a high output 3 stage smart charger. I'm assuming that would be an upgrade, and I know I haven't done it.

My 8 year old bargain basement trailer came with a 35 amp, 3 stage charger/converter. It may not be all that smart or powerful, but it maintains my 6v batteries fine. Make sure you take the time to learn just what you have before investing in something more, that very likely isn't needed.

Hello neighbor
Congrads on the new rig. Lots of great places to camp close to our home. I buy all my RV , Boat batteries at Costco. Good price, good battery. I run twin group 27 deep cycle marine. We can dry camp about 4 days if we are careful. At that point the TV needs more voltage. Best of Luck.